Polymorphisms in a disintegrin and metalloprotease 33 gene and the risk of chronic obstructive pulmonary disease: A meta‐analysis

A number of polymorphisms in a disintegrin and metalloprotease 33 ( ADAM33 ) gene have been implicated in susceptibility to chronic obstructive pulmonary disease ( COPD ). However, results to date have been inconclusive. We conducted meta‐analyses to investigate the associations between multiple polymorphisms in ADAM33 gene and COPD susceptibility. P ubMed, E mbase and C hinese databases ( W anfang and C hina National Knowledge Infrastructure) were searched for eligible case‐control studies. We extracted data and used meta‐analysis to calculate pooled odds ratios with 95% confidence intervals to evaluate the strength of associations. Twelve studies containing six ADAM33 polymorphisms ( F +1, S1 , S2 , T1 , V4 and Q ‐1) were identified, which involved 2630 cases and 4376 controls. ADAM33 S1 polymorphism showed stable and significant associations with COPD risks among the Chinese and smoking populations, and Q ‐1 polymorphism showed stable and significant associations with COPD risks among the overall populations. In subgroup analyses, T1 and Q ‐1 polymorphisms were significantly associated with COPD risks among the C hinese and smoking populations, and among the C hinese, Caucasians and smoking populations, respectively. However, none of the significant results was stable in sensitivity analyses. With respect to F +1, S2 or V4 polymorphism, there was no evidence of any significant association with COPD risks in either the overall or the subgroup analysis. The results of this meta‐analysis indicate that ADAM33   S1 polymorphism is a risk factor for COPD among the C hinese and smoking populations, and that Q ‐1 polymorphism is a risk factor for COPD among the overall populations.